Pretty plugin labels, preserve plugin app provenance during MCP tool refresh (#15606)

- Prefer plugin manifest `interface.displayName` for plugin labels.
- Preserve plugin provenance when handling `list_mcp_tools` so connector
`plugin_display_names` are not clobbered.
- Add a TUI test to ensure plugin-owned app mentions are deduped
correctly.

codex-rs/tui/src/chatwidget.rs

@@ -8946,6 +8946,10 @@ impl ChatWidget {
 
     fn on_list_mcp_tools(&mut self, ev: McpListToolsResponseEvent) {
         if self.connectors_enabled() {
+            let plugin_provenance = McpManager::new(Arc::new(PluginsManager::new(
+                self.config.codex_home.clone(),
+            )))
+            .tool_plugin_provenance(&self.config);
             let mut connectors_by_id: HashMap<String, connectors::AppInfo> = HashMap::new();
             for tool in ev.tools.values() {
                 let Some(meta) = tool.meta.as_ref().and_then(serde_json::Value::as_object) else {
@@ -8988,7 +8992,9 @@ impl ChatWidget {
                             install_url: None,
                             is_accessible: true,
                             is_enabled: true,
-                            plugin_display_names: Vec::new(),
+                            plugin_display_names: plugin_provenance
+                                .plugin_display_names_for_connector_id(connector_id)
+                                .to_vec(),
                         }
                     });
             }